Turfgrass diseases are difficult to understand because the organisms causing the problems are rarely observed. Fortunately, grasses maintained using proper cultural practices (water, mowing, and fertility) are not as likely to become diseased or be as severely damaged as grasses not receiving proper care.
There are two common patterns of turfgrass disease symptoms. One is a circular patch of turfgrass, either small or large, that is no longer uniformly green. The second is turf that has “spots” on the leaves. If disease patches are present, examine the leaves and roots in these patches for characteristic symptoms of disease and signs of actual fungus. The best time to observe fungus in the lawn is in the early morning when dew is still present. For turf with spots, note the color and shape of the spots.
There are three steps to disease management. First, correctly identify the disease. Second, identify the conditions promoting disease development. Third, identify the management techniques that will alter or eliminate these conducive conditions.
It is important to know and realize that control of plant diseased leaves must be preventative. Once a plant gets a disease, we cannot cure it. All we can do is protect the undiseased leaves and new leaves as they emerge. The diseased leaves drop, and the plant thus appears to have been “cured” of the disease.
To try to describe there even a part of the thousands of diseases which attach ornamental plants is prohibitive. So, we will describe only a few of the most common diseases which we encounter here in beautiful Southwest Florida.
BROWN PATCH: Brown Patch Fungus kills St. Augustine, Bahia, Rye, Bermuda, Zoysia, and Centipede grasses in more or less circular patches that begin as small spots and may expand to several feet in diameter. In these areas the grass blades are not usually matted together. It may also cause a thinning of the turf over a large area. This Fungus usually occurs during warm, humid weather.
DOLLAR SPOT: Dollar Spot Fungus kills St. Augustine, Bermuda, Zoysia, Bahia, and Centipede grasses in distinct patches that are 2 to 3 inches in diameter. These patches take on a bleached Straw color. In several cases small patches may coalesce so that large areas are affected. Leaf spot-type lesions may be seen on the blades of grass at the outer margins of the small patches. Dollar Spot Fungus occurs during mild to warm humid weather.
GRAY LEAF SPOT: Gray Leaf Spot Fungus develops round to oblong spots on the leaves of St. Augustine and Rye grasses that are brown to ash colored with purple to brown margins. Spots may be covered with gray mold in warm, humid weather. Lesions may also occur on the stems. In severe cases leave have a scorched appearance. This fungus is prevalent during the rainy summer months.
FAIRY RING: Fairy Ring Fungus is difficult to control on all grasses. Initially, the grass is stimulated and greens up in a circular pattern. In a few weeks, the grass in these areas will begin to decline. Mushrooms are often present in the areas affected. Fertilizers and watering often help in the declining areas.
The elimination of most fungi can be prevented or controlled with traditional spraying or dusting. To repeat, this is not a cure. To prevent these fungi from appearing and damaging your turf, the turf must be sprayed before and not after the disease strikes. It must be kept on the turf as constantly as possible for the period the disease period is likely to attack.
Collier Pest Control does not offer monthly or other scheduled turf maintenance programs. Collier Pest Control does offer one time correction treatments for fungi and other turf damaging problems. If you have been told or suspect you may have a fungus problem in your lawn, call Collier Pest Control, 239-455-4300 for a Free Inspection or a complete explanation to any of our services. You also can look us up on our web site at collierpestcontrol.com or Email us at firstname.lastname@example.org . Remember Florida does not have to be shared with insects.